1. Field of the Invention
The present invention relates to a medical device having data generating components forming a data generating unit and data processing components forming a data processing unit, the data generating unit and the data processing unit being displaceable relative to each other, as well as an arrangement for transferring data from the data generating unit to the data processing unit.
2. Description of the Prior Art
In many branches of technology, the problem has occasionally arisen that high volumes of data must be transferred from data generating unit to data processing unit, which can be displaced relative to each other. In medical technology, this problem exists in X-ray devices that have a C-arm that can be displaced relative to a device part.
Such an X-ray device is disclosed in German OS 197 46 096, corresponding to U.S. Pat. No. 6,079,876. The X-ray device is provided for generating 3D images from a series of 2D projections that are registered from various directions.
In C-arm radiography devices such as this, the image data that are acquired by an image pick-up unit that is arranged at the C-arm must be transferred to an image reproduction unit that is arranged in or at the device part. Conventionally, coaxial cable has been used for the transfer of data from the C-arm to the device part. Given an open cable guidance, this technique is easy to master. In contrast, the concealed cable guidance with cables that run in the C-arm and that can be wound and unwound on cable drums, as is described in German Patent 197 43 215, corresponding to U.S. Pat. No. 6,065,710, is more problematic. This is because suitable cable guidance for winding and unwinding the cable on the cable drums is required, as well as because the cable is subjected to many stressful bending events in procedures to displace the C-arm relative to the device part.
It is an object of the present invention to provide a medical device of the above described type wherein the transfer of data between data generating unit and data processing unit which are displaced relative to one another is simplified.
This object is inventively achieved in a medical device having a data generating unit and a data processing unit that can be displaced relative to each other, as well as an arrangement for transferring the data from the data generating unit to the data processing unit, wherein the unit for transferring the data has a hollow conductor and an antenna that operates in conjunction with the hollow conductor, which can be displaced relative to each other in a defined manner in the relative displacement of the data generating unit and the data processing unit. In a preferred embodiment of the invention, the hollow conductor is connected to the data generating unit, and the antenna is connected to the data processing unit. For the data transmission, the data which are generated by the data generating unit are modulated onto a carrier signal which, for medical applications, has a carrier frequency of 5.8 gigahertz, for example, and are coupled into the hollow conductor. The antenna, which is disposed in a defined manner relative to the hollow conductor, i.e. in a geometrically defined manner, receives the carrier signal, i.e. couples the carrier signal out of the hollow conductor, in a contact-free manner, so that after the carrier signal is demodulated the generated data are available to the data processing unit in their original form. The utilization of the hollow conductor and the antenna that is oriented relative to the hollow conductor, which can also be displaced relative to each other when the data generating unit and the data processing unit are displaced relative to each other, makes it possible to forgo transfer of the data by cable, and specifically avoids problems that are caused by the cable guidance and the winding and unwinding of cables in the displacement of two units that can be displaced relative to each other.
In a further preferred embodiment of the invention, the hollow conductor is provided with a slot along which or in which the antenna is guided in the displacement of the data generating unit and the data processing unit relative to each other. In this way, the antenna can couple the modulated carrier signal out of the hollow conductor with a high efficiency.
In the journal Elektrotechnik (73, Vol. 11, Nov. 23, 1991; 48-53), in an article by Uwe Bueltman entitled xe2x80x9cSchlitz im Kleidxe2x80x9d, a data bus or rail is described which is provided for the contact-free transmission of data in automation technology and which has a slotted hollow conductor and an antenna which is guided in the slotted hollow conductor.
In another version of the invention the hollow conductor is provided with a perforation along which the antenna is guided in the displacement of the data generating unit and the data processing unit relative to each other. In this context, a perforation means an intentional thinning of the material of the hollow conductor or a series of local openings in the hollow conductor which is or are sufficient to enable electromagnetic waves that are conducted in the hollow conductor to exit the hollow conductor. The perforation can be constructed as a continuous perforation along the path of displacement of the antenna. The perforation likewise allows reception of the modulated carrier signal by the antenna and thus a contact-free transfer of data.
In a further embodiment of the invention, the data generating unit is an image pick-up unit, and the data processing unit is an image reproduction unit. The data that are generated by the data generating unit being transferred to the data processing unit in digital form in accordance with another variant. If the image pickup device generates analog data, the analog data are first converted into digital data by an analog/digital converter and then modulated with a carrier signal by a modulator. The modulated carrier signal is coupled into the hollow conductor on the image pick-up device side and is coupled out of the hollow conductor by the antenna on the image reproduction device side. Next, the modulated carder signal is fed to a demodulator for recovering the digital data and to a digital/analog converter for recovering the analog data. If the data are delivered by the image pick-up device in digital form, and the image reproduction device is able to process digital data, the analog/digital and digital/analog conversions can be omitted, In this way, given 16 bits of data, 30 images per second and a 1 k2 image matrix (1000xc3x971000 pixels), data volumes of 480 megabits per second and higher can be transferred from the image pick-up device to the image reproduction device.
In another embodiment of the invention for medical use of the device. The Invention is employed, for instance in a radiography device. This can be a radiography device with a C-arm that is mounted in a support of the radiography device such that it can be displaced along its circumference and that is provided with the image pick-up device. The hollow conductor extends along the circumference of the C-arm. The antenna can be disposed at the support of the C-arm. The antenna thus can be easily oriented in a defined manner relative to the hollow conductor. During displacements of the C-arm along its perimeter, the antenna, which is stationary relative to the hollow conductor, is guided either along or in the slot of the hollow conductor in accordance with one version of the invention, or along the perforation of the hollow conductor in accordance with the other version of the invention.